This chapter discusses the pediatric use of dual-energy X-ray absorptiometry (DXA), quantitative computed tomography (QCT), peripheral QCT (pQCT), quantitative ultra- sound (QUS), magnetic resonance imaging (MRI), and X-ray radiogrammetry for bone mass measurement. These techniques can be compared using several criteria, including speed of measurement, radiation exposure, cost, and regions of the skeleton that can be scanned. These techniques also vary in accuracy (the difference between bone measurement and ash weight) and precision (the reproducibility of repeated measurements). For clinical purposes, precision is of greater importance than accuracy. QCT and MRI can distinguish trabecular from cortical bone, whereas DXA provides only a composite measurement of both compartments. There are differences in the availability of normative pediatric data to be used as reference values when interpreting scans performed for clinical purposes. The recognition of importance of early bone health has increased the demand for bone mineral assessments in children and adolescents. For clinicians, densitometry is important for screening the bone health of young patients with myriad chronic diseases associated with low bone mass and fractures early in life. The goal of mass assessments in this setting is to identify patients with skeletal fragility and to monitor response to therapy.
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)